declare namespace Ext {
    export namespace data {
        export interface ErrorCollectionConfig {
            allowFunctions?: boolean;
            defaultSortDirection?: string;
            listeners?: object;
            multiSortLimit?: number;
            sorters?: Ext.util.Sorter[] | object[];
            sortRoot?: string;
        }

        export class ErrorCollection extends Ext.util.MixedCollection  {
            public getByField(fieldName?: string): object[];
            public isValid(): boolean;
        }
    }
}